The applicant's successful and popular vehicle recovery system sold under the trademark LoJack® includes a small electronic vehicle locating unit (VLU) with a transponder hidden within a vehicle, a private network of communication towers each with a remote transmitting unit (RTU), one or more law enforcement vehicles equipped with a vehicle tracking unit (VTU), and a network center with a database of customers who have purchased a VLU. The network center interfaces with the National Crime Information Center. The entries of that database include the VIN number of the customer's vehicle and an identification code assigned to the customer's VLU.
When a LoJack® product customer reports that her vehicle has been stolen, the VIN number of the vehicle is reported to a law enforcement center for entry into a database of stolen vehicles. The network center includes software that interfaces with the database of the law enforcement center to compare the VIN number of the stolen vehicle with the database of the network center that includes VIN numbers corresponding to VLU identification codes. When there is a match between a VIN number of a stolen vehicle and a VLU identification code, as would be the case when the stolen vehicle is equipped with a VLU, and when the center has acknowledged the vehicle has been stolen, the network center communicates with some of the RTUs of the various communication towers (currently there are 130 nationwide) and each tower transmits a message to activate the transponder of the particular VLU bearing the identification code.
The transponder of the VLU in the stolen vehicle is thus activated and begins transmitting the unique VLU identification code. The VTU of any law enforcement vehicles proximate the stolen vehicle receive this VLU transponder code and, based on signal strength and directional information, the appropriate law enforcement vehicle can take active steps to recover the stolen vehicle. See, for example, U.S. Pat. Nos. 4,177,466; 4,818,988; 4,908,609; 5,704,008; 5,917,423; 6,229,988; 6,522,698; and 6,665,613, all incorporated herein by this reference in their entirety.
Typically, there are two telephone lines interconnecting each RTU to the center. If a stolen vehicle is suspected of being located in the eastern United States where there are 21 towers each with an RTU, 21 telephone calls would be made so that each RTU begins to transmit a message which, if received by the VLU in the stolen vehicle, activates the VLU transponder so law enforcement personnel can then locate the stolen vehicle using a VTU.
Calling each RTU therefore takes time wherein a thief can attempt to thwart recovery efforts. Calling each RTU also incurs costs. Finally, in the case where there is a problem with an RTU land line connection with the center, that RTU win not begin transmitting the message required to activate the VLU in the stolen vehicle.